Two weeks ago, Emory Alexander left his 10-month-old daughter, Kimora, with his mom, and said he'd be back in a little while. Less than two hours later, he was shot dead on a sidewalk outside an Allapattah home.

Witness accounts and forensic evidence have been so hard to come by in the nine days since the Sept. 14 murder, that detectives and family members gathered at Miami police headquarters Tuesday asking for the public's help.

"We have no idea if the offender was on foot, in a car, or on a bicycle," said Miami Detective John Ruinque. "We're pretty sure there were several people out there who saw something."

Alexander's mom, Adriane Alexander, said she was the last person to see her son that night, and he didn't mention where he was going.

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The silence surrounding the death has police believing anyone who may have witnessed it or knows about it fears retaliation.

Police wouldn't go into details on working theories. When Alexander's mother was asked if her son ever expressed fear that he might be in danger, she only offered, "Something like that."

"He wasn't a perfect child, but he was trying to get himself together," she said.

The 10:45 p.m shooting happened several miles from Alexander's home in unincorporated Miami-Dade County. The 19-year-old was found bleeding on a sidewalk in front of a home at 1436 NW 43rd St.

Several calls were made to 911 after the shots were fired. Police haven't said what type of weapon was used or how many shots there were.

Tuesday, family members visited police headquarters asking the shooter to turn himself in and demanding information. Besides Alexander's mother, his grandparents, an aunt, the mother of his daughter and Kimora were there.

A framed picture of Emory Alexander rested on a conference table in front of them.

Also on hand were members of the group Love Over Violence and Evil, created two years ago to encourage kids to put their guns down.

They all wore T-shirts that read "Choose Love Over Violence."

"This family is really hurting. Whoever did this to my grandson, that was a cowardly act. Whoever you are, you hear me out there. Turn yourself in. This ain't the wild, wild, west," said grandfather Harold Alexander.

"You tore up this family. Somebody had to see something. It might be your family member one day."